Technical Field
The present invention relates to process analysis and, more particularly, to estimating waiting and service times from incomplete event logs.
Description of the Related Art
Performance analysis is frequently used in redesigning processes to increase their efficiency. One frequently used type of analysis is calculation of waiting time and service time of process activities from an event log. The average waiting and service times of individual activities and resources enable the redesigner to discover bottlenecks in the process.
Process management tools (e.g., a process aware information system (PAIS)) will record event details. For example, a PAIS may record both start-event and end-event activity for a variety of events. This makes calculating service time and waiting time trivial, simply by subtracting event timestamps.
However, it is not always possible to access both start- and end-event information. In many legacy event logs, only one of the two types of information will be recorded. One example of such an event log is in, for example, webserver logs, which record only the start time of an event and do not record the time at which the event completes.
In such a case, the only information available is the transition time from one event to the next (i.e., the time between respective start-event timestamps or respective end-event timestamps). While more modern process managers will handle both, some customers may wish to have analyses of process timing to improve their existing, legacy systems.